The purpose of the study was to compare the effect of voluntary pelvic floor muscle (FFM) contraction and vaginal electrical stimulation on urethral pressure. Twelve women with genuine stress incontinence, mean age 49.4 years (range 33-66) participated in the study. The urethral and bladder pressures were recorded simultaneously through a double-lumen 8 Ch catheter. The patients first performed three voluntary PFM contractions. Then two electrical stimulators, Conmax and Medicon MS 105, 50 Hz, were used in random order. A visual analog scale was used to measure pain and discomfort. Pain was reported to mean 6.8, SEM 0.64 (range 0.7-9.9) and mean 6.1, SEM 0.81 (range 0-9.1) with Conmax and Medicon MS 105, respectively. The mean paired difference in favor of voluntary contraction with Conmax was -8.0, SD 6.7, P = 0.0067, and with Medicon MS 105 it was -12.2, SD 5.9, P = 0.0022. The results demonstrated that voluntary PFM contraction increased urethral pressure significantly more than did vaginal electrical stimulation.